Collection equipment for spray drying apparatus



Dec. 20, 1955 F. E. BONNER 2,727,668

COLLECTION EQUIPMENT FOR SPRAY DRYING APPARATUS Filed Nov. 24, 1952 2 Sheets-Sheet l IN V EN TOR.

FRANK E. BONNER TMM TA M ATTORNEYS Dec. 20, 1955 F. E. BONNER 2,727,568

COLLECTION EQUIPMENT FOR SPRAY DRYING APPARATUS Filed Nov. 24, 1952 2 Sheets-Sheet 2 INVENTOR.

FRANK E. BONNER BY P ATTORNEYS 2,7216% COLLETION EQUIPMENT, FOR SPRAY DRYING APPARATUS Frank fiimiter, fiaytb'n, (this, tissig hr ta rh Cornaiohweaith Ehgiheafihgeenipahy a: our-o,- Dayton, Ohio, cameras-oh at one Application November 24; 1952, Serial Not 355315 4 Claims; "(Geish 58 This ihvehtien relates to spray drying equiph eht aha more particularly to eq ipment useful in ee hectieh with the ee11eet' 'ofjiiateiial asjit is spray dried. V I,

Tl'le pnma-i'y objective of this invention is to preside at fle'nsle means for "the collection and shipment of spra dried material. 1 h a same material which are spray dried are equirea he treated, eeile eted and shipped underconditions of absolute sterility. shah a material is hydrolyzed eextra a blood plasma volume expander, which in the state isa urry white pq'wder. It is aecoidih ly ah bbject of this iiive'ntiifin to describe eouectieh means for such a l f 'r The invention will he e e fully understood by refer three to the renewing detailed desefi noh aha aeeem anw ingldrawing's wheieiii: I I V Figure 1 illustrates sehehiatieany a cehvehtiehal spray drying system; W

Figure 2 is a view partially in section at an arrange; meat at a comedian means embodying the precepts or this invention; p p u F gure 3 illustrates a step in the removal or the eelie'ti oh me 'ansfrorn the system; and p Figure 4 illustrates the packaged condition er the sterile material. i g Referring to the nrawi gs tliereis indicated at i in Figure 1 a s ray dryer rrsrh which dried frnaterial 3 is blown through a first conduit 5 to a receiver 7. since the dr er 1 operates at eehainhhspr ele atedteihpera ture the air passing with the ma terial 3 through 'c'oii'diiit 5 is heated to a considerable degree and thirst he ere nausea from the equipment; eo sequehtiy a powers in a seems conduit 11 is honhnly prhvrded for withdi 'avval hr the hot air to the atmosphere from the eths wise eiesea sysrei I f v Brewer 9 in its operation however, together with the eflet er the air rushing thrcugh the onduits ast receiver 7, creates a fsuc'tion pressure in this receiver; sings e materials which have been spray aried are arr'nally fiuffy, light inaterialga large quantity of the pram drawn through conduit 11 and lost.

This suction pressure necessarily requires that the fe ceiver 7 have substantially rigid walls to resist the outside pressure. Accordingly, heretofore, glass jars or bottles have been employed the teeei em. Due to the pressure gradient rewards line 11 such jars are not readily completely fillable with dried dextr'an; further due to the weight and fragility of the container the jars are not normally employable as shipping units and therefore it has been the practice to transfer the jar collected material to flexible sterile bags.

Such bags have not up to now been usable as receivers as the pressure conditions prevailing (Figure 1) cause the bag to collapse thus inhibiting the entry of the dried material thereto and increasing product losses.

The structure set out in Figure 2 illustrates a system for overcoming the disadvantages now present in the art. Thus in Figure 2 there is shown at (see Figure 1 United States p r 2,727,668 l a'tnted flee. it), 19%

arse a t hi'rd eo a'ui extending downwardly from the outlet of conduit 3, the remainder or the equipment except for ree'eiver 7 being the same as described hereinbefore. t v v I As shown in Figure 2 receiver replaced by a Qql: lectoiunit having an inner sterilized air-impermeable bag 1 9, preferabl of polyethylene, secured to the third eahduit 10 at 14 hy twine hr other suitable tieing means 22 capable of forming an airtight seal between the throat 20 er the bag and the conduit portion. This air-imperineable bagis also proyided at 16 with a second tieing means which may be integral with the bag but which when the apparatus is tunc'tioning is free as depicted in Figure 2. The bag 19 may be either horiiontally or vertically positioned as desired. a J p Positioned outside or, bag 19 is an air-impermeable shell '18 which may be of rubber, polyethylene, rigid plastit: 01'' even metal; where rigid plastic or metal is employcd adequate seals must be provided to render the shell '18 airtight. Where this outer shell 18 is or" 3. flexible material, such as polyethylene, stays are provided on the internal periphery to prevent the shell collapse upon application of differential pressures thereto. It is to be noted that where polyethylene is employedthe wall thickness and frequency of the supports should be sufficient to resist ra ture at thiscasingf The s'upporting structure comprises a ring 25 and a semen/ a larger ring 2 7 interconnected aplu-rality stays 29 shaped to conform to the expanded shape of the outer shell 18;

Accordingly Figure 2 a metal plate 15 closely engag; ing the conduit 10 receives thereon a flanged port-ion :21 of shell 18, and suitable clamping means 17 secure the same in airtight relation; gasket meansas required by the rigidity of the members may be employed between the flanged portions and the plate, and between the conduit and plate. Alternatively as indicated in Figure 2 the plate "may be weldedto the conduit as at 4 Shell I8 is also provided at 24 with a connection 26 which engages over conduit 28 connected to suction pump 30 Further as shown Figure 1 it will be noted that condui't it? is also .provided with a line 32 having a valve 34 and a sample collector 36, Under normal operating conditions with material flowing to bag 19 "the opening of valve 34 will cause a sufliciently low pressure in corllec'tor 36 for a sample of the material to flow thereto, howeversince under some flow conditions it may be di cult to fill the collector suificiently an outer casing {38 may be fitted to a plate having clamping means 49; the arrangement being similar to that of plate 15 and clamps 17. Then with the apparatus operating and ayacuu'rn condition created in the casing 38 through line42 which is also connected to pump 30 the collector 36 is maintained completely open for receipt of material. This sampling apparatus is accordingly similar to the primary equipment hereinbefore described and is of particular utility where periodic testing for sterility is required.

In the operation of the apparatus with the air and, for example, flufiy dextran flowing through line 3, blower 9 (Figure 1) is-operated to withdraw the hot air through line 11-. However simultaneously with the blower opera tion suction pump 30 is actuated to "cause 'a 16W p'res'stire in the shell 18; this efiects a difierential pressure between the interior and exterior of the polyethylene or other airimpermeable bag 19 causing the bag to be expanded. The drop in pressure in shell 18 need not generally be great to effect this expansion for under usual operating conditions the pressure within bag 19 will only be slightly less than atmospheric and for satisfactory functioning it is only required that the pressure in the chamber defined by the bag and shell be somewhat less than that in the bag itself.

Accordingly with pump 30 operating the bag 19 may be readily filled with dextran. Experience indicates that some slight amount of dextran will still pass through line 11 and be lost but the increase in speed of operation due to the use of the flexible inner bag compensates somewhat for this factor.

The increased efliciency stems from the several advantages of the inventive arrangement. Initially, the flexible bag is much easier to mount than the glass jars, and this is the case even though the shell also must be positioned for each cycle. The positioning for filling is relatively simple since it is only necessary to first secure a bag 19 on conduit 10 and then mount shell 18 over the bag and the conduit in secured relation with the latter.

When demounting filled bag 19 it is not necessary to shut off the spray drier first although such action is preferable as atmospheric pressure is then substantially immedidiately established in the bag. Where sterile material is a under process the equipment should be located in a sterile room and under this condition the air entry to the bag will not be detrimental.

Preferably also the operation of pump 30 ceases simultaneously with that of the spray drier; the vacuum shell 18 is then broken at 17 and the shell slipped or expanded down over bag 19 to permit sealing thereof at 16 (Figure 3). In this connection it is to be noted that the bag and shell may have any suitable dimension and degree of expansibility to permit passage of one with respect to the other. Bag 19 may then be untied at 22 and removed from the apparatus; shipment of bag 19 may then be made and no necessity arises for transfer of the material until it is ready for use.

Alternatively in the demounting procedure the spray drier may operate until after pump 30 is cut off, the seal broken at 17 and the twine or string 16 tied. Under this condition some slight loss of material may occur due to the lower pressure on the bag interior but generally the bag is sufliciently filled to overcome this slight defect and the bag will not collapse, since under this condition the air-impermeable bag is under a slight vacuum when string 16 is tied and the possibility of any slight contamination is lessened.

I It is to be noted that no necessity need arise for demounting the shell from the pump 30 since the shell 18 and connection 26 may he slid over the conduit 28, and that therefore it is only necessary to connect and disconnect at the plate 15 when producing.

The flexible polyethylene bag material (Figure 4) offers several important advantages. First, it is rendered sterile by simple heating; second, it conforms readily to any shape, and close packing arrangements may be effected for shipping; thirdly, it is strong and chemically resistant, and readily sealable; fourth, it is light in Weight; and fifth, is relatively inexpensive since it may be formed from flat sheet material.

Other suitable air-impermeable bag materials however may be employed as, for example, treated fabrics, and materials such as the cellophanes and plastics depending upon the particular purpose. However polyethylene is considered preferable because of its versatility in substantially all respects.

It will be understood that this invention is susceptible to modification in order to adapt it to different usages and conditions and accordingly, it is desired to comprehend such modifications within this invention as may fall within the scope of the appended claims.

I claim:

1. A collection unit and spray drier equipment in combination, a spray drier having a first conduit through which heated air and dried material flow, a second conduit communicable with said first conduit for the exhausting of heated air to the atmosphere, and a third conduit communicable with each of the other two, the said collection unit comprising an inner air-impermeable bag secured over the third conduit, the bag being of a flexible material and expandible, an outer casing defining a spacing with said impermeable bag, and means associated with said casing operable to reduce the pressure in said spacing below that in said bag to make said bag in an expanded condition for receipt of dried material.

2. A collection unit and spray drier equipment in combination, a spray drier having a first conduit through which heated air and dried material flow, a second conduit communicable with said first conduit for the exhausting of heated air to the atmosphere, and a third conduit communicable with each of the other two, the said collection unit comprising an inner air-impermeable bag secured over the third conduit, the bag being of a flexible material and expandible, an outer pouch having supporting stays and defining a spacing with said air-impermeable bag, and means associated with said pouch operable to reduce the pressure in said spacing below that in said bag to make said bag in an expanded condition for receipt of dried material.

3. In a spray drier system in which the flow of spray dried material is subjected to a vacuum pressure for the elimination of heated air, a trio of intercommunicable conduits a first one of which is adapted to pass heated air and spray dried material to the other two and a second one of which is adapted to pass heated air to the atmosphere, the third conduit having secured thereto a collection unit for spray dried material comprising an inner airimpermeable bag secured over the third conduit, the bag being of a flexible material and expandible, an outer casing defining a spacing with said air-impermeable bag, and means for removably securing one end of each said bag and casing in airtight relation with the said conduit to permit the atmospheric pressure in said spacing to be reduced below that in said bag to make said bag in an expanded condition for receipt of dried material.

4. In a spray drier system in which the flow of spray dried material is subjected to a vacuum pressure for the elimination of heated air, a trio of intercommunicable conduits a first one of which is adapted to pass heated air and spray dried material to the other two and a second one of which is adapted to pass heated air to the atmosphere, the third conduit having secured thereto a collection unit for spray dried material comprising an inner air-impermeable bag having a throat defining an opening for air-tight reception on said third conduit, the bag being of a flexible material and expandible, an outer casing having a neck extending over said throat in sealing relationship therewith, said casing and bag defining a spacing therebetween, and means associated with said casing operable to reduce the pressure in said spacing below that in said bag to make said bag in an expanded condition for receipt of dried material.

References Cited in the file of this patent UNITED STATES PATENTS 1,037,824 Fasting Sept. 3, 1912 1,372,190 Randal Mar. 22, 1921 2,513,143 Carter June 27, 1953 

